Servo tracking device for endless members



Feb. 7, 1956 T. E. DUGLE ETAL 2,733,555

SERVO TRACKING DEVICE FOR ENDLESS MEMBERS Filed March 2. 1954 4Sheets-Sheet l INVENTORS THOMAS E. DUGLE CARL E. CLUTTER BY ALVIN F. ALT

SERVO TRACKING DEVICE FOR ENDLESS MEMBERS Filed March 2, 1954 4Sheets-Sheet 2 INVENTORS- THOMAS E DUGLE CARL E.CLUTTER BY ALVIN F. ALT

Feb. 7, 1956 5 DUGLE ETAL 2,733,555

SERVO TRACKING DEVICE FOR ENDLESS MEMBERS Filed March 2, 1954 4Sheets-Sheet 3 VENTORS THOMAS E. DUGLE CARL E. CLUTTER BY ALVIN F. ALT

Feb. 7, 1956 'r. E. DUGLE ETAL 2,733,555

- SERVO TRACKING DEVICE FOR ENDLESS MEMBERS Filed March 2, 1954 4Sheets-Sheet 4 I22 rloo r A02 lll L INVENTORS THOMAS E. DUGLE (:A E.OLUTTER I \7 BY AL F. ALT

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SERVO TRACKING'DEVICE FOR ENDLESS MEMBERS Thomas E. Dugle, Cincinnati,Carl E. Clutter, Mason, and Alvin F. Alt, Deer Park, Ohio, assignors toPlanet Products Corporation, Cincinnati, Ohio, a corporation of Ohio 7 aApplication Mai-chz, 1954, Serial No.- 413,643

" 11 Claims. (Cl. 51-135 This invention relates to a servo trackingdevice for endless members, such as belts, webs or'the like, the

tracking device in the form of a compact unit which may United StatesPatent be associated with orattached toexisting machines util- I 'izingendless members, such as, by way of example, conventional belt grinders,forimproving and accurately con- 1 trolling the tracking characteristicsof the endless members, thereby increasing the overall efliciency of themachine. a

A further object of the invention is to provide a servo tracking devicewhich includes simple, easily accessible means for enabling an operatorto alter the operating characteristics of the device while an endlessmember is passing over the tracking shoe thereof.

, Anotherobject of the invention is to provide a servo tracking devicewhich is so constructed and arranged as to facilitate its massproduction for both a right and left mounting whereby only the endplates differ, .all theother elements of the device being reversible.

Another important object of the invention is to provide a servotrackingdevice which may be automatically operatedfor' controlling the trackingof an endless member passing over a shoe to a substantially fixed axialpath, or

which ay be automatically operated for imparting a predetermined, cyclicsidewise motion to .the endless member. y I p A further object of theinvention is to provide a servo tracking device having the hereinabovedescribed characteristics which includes a conveniently accessible,"out- 'wardlyiprojecting, axially vshiftable element which maybe.actnated by any suitable external means for imparting cyclic sidewisemotion "to an endless member passing over the tracking shoe.

, These and other objects are'attained by the means de- I scribed hereinand as disclosed in the accompanying drawings, in which:

. Fig. l is a side view of a belt grinder provided with a seryo,tracking device embodying the teachings of ,the present invention.

2 is a partial front view of the device of-Fig. l.-

. Fig. 3 is a view taken on linev 3-3 of Fig. 2.

Fig.- 4 is a front elevation of a servo tracking device,

7 ,per se.

Fig. 5 is a $1363.! view of the device of Fig.- 4.

.disa topviewofFigS.

. .is a iew of the right end of :FigQ4.

as a vie- 9 the. f end r a sectional view taken on line 9-9 of Fig. 7.

r. 2,733,555 Patented Feb. 7, 1956 '2 Fig. I0 is a sectional view takenon line 10-40 of Fig. 7.

Fig. '11 is a sectional view taken on line 11-41 or s- V v r.

Fig. 12 is a sectional view takcnoii line 12-12 of Fig. 4. p p

Fig. 13 is a sectional view taken on line 13-13 of Fig. 7. I

, At the outset it should be understood that presentinvention isdirected to a tracking device for webs the 'widtlrs of wnichare equal to,orless than the width of at acking shoe over which the webs are passed,as contrasted with and distinguished from the'well establishedcumbersome means for guiding wide ivebs'of material by passing them overwider rollers which aremoilnted so that one end may be shifted relativeto .an opposite end.

Thcscrvo tracking device comprises a tracking. shoe 20 over which ancndlessmember or belt 22 passes, said membcr'including oppositesideedges 24 and 26. Edge 26 of the endless belt normally contactsfinger 30, and sidewise shifting of the belt relative to tracking shoe,20 will result in a corresponding movement of the finger to the rightorto the left. finger movement is utilized for controlling a servomechanism which is operative to impart a selective tilting motion .tothe tracking shoe for shifting the belt .thereover back to its original,desired or normal position thereon.

With particular reference now to Figs. 4 and 7, will be noted thatfinger 30 is secured by clamp 31 to arm 32 which is securedby' clamp 3 3to rotatable shaft 34. i,

As best illustarted in Figs. 9 and 12, lever 36 is secured toshaft 34,the free end of the lever abutting against an end of an axially-s'hiftable valve spool 38 which is norgmally and yieldably maintainedin contacting relationship with lever 36 by means of springs 40. Spool38 is provided with a bore 42 in which the springs are partially re,-ceived. The free end of the spring which projects from the spool isreceived within axial bore 43 of cap 44.

Cap 44 is received socket 46 of shaft 48, said socket including akey-way 50 engageable by pin 52, .note Fig. 10,' for limiting the socket,tc'endwise' or axial movementonlys p A sleeve 54 is slidablyreceived'within bore 55 of housi'ng 110,said sleeve including an axialbore 57 in which the spool 38 is received forendwise axial movement.

The left, or free end of socket 46 engages the right end of sleeve 54,whereas thelc'ft end of the sleeve is engaged by the right, or free endof secretes carried by guide shaft 58 for aspring 60, one end of whichabuts against the left orrear end 62 of socket 56, the other end ofwhich is seated within bore 64 inboss 67 of end plate 66.

That end of shaft 48 remote from socket '46 terminates in a threadedportion 70 whichengages' the internally threaded socket '72 of-a spurgear 74 rotatably received within well 76 of end plate 78. t

The outer end of gear 74 is provided with a bearing member or end capwhich abuts against a fixed stop 141, denoted in broken outline in Fig.10, or against the :end of an axially :shiftable shaft 150,- Figs '2, 3,'5, 6 and supply-lineprovided in end plate 78 :fo'r normally andcontinuously' supplying pressure to cylinder 96 and against end face 98of piston 90.

Pistons 90 and 92 are rigidly interconnected by means of a rack 100, andin the preferred embodiment of the invention piston 92 has approximatelytwice the area of piston 90. The numeral 111, Figs. and 11,.denotes arack guide.

With referencenowto Fig. 5, the pressure lines have been indicated bythe numeral 94 and the exhaust lines by the numeral 104. The line bywhich intermediate port 82 is conneeted to the outer end of cylinder 106is indicated by the numeral 102. L Inpassing it will be noted thathousing 110, in which cylinders'96 and 106 are provided, may be soconstructed as to permit it"to be usedas a'right or left hand device,that is, "pistons'90 and 92 and end plates 66 and 78 may be reversed endfor end from the positions illustrated in Figs. 9"and 10. Housing 110 isprovided with a through here 112 which provides the cylinder wall forpiston 92.' An adapter sleeve 114may be utilized for restricting bore112to provide cylinder 96 to accommodate piston 90.

With reference now to Fig. 4, it will be noted that when belt 22' isshifted toward the right, finger 30, arm 32 and shaft 34 will be movedin a counter-clockwise direction.

"'At this point it should'be understood that counterclockwise 'rotationof shaft 34 'of Fig. 4 will occur as clockwise rotation of the shaft asillustrated in Fig. 9.

.Lever 36 will thereforebe turned in a clockwise direction for bodilyshifting spool 38 to the right against the coun terforce of spring 40,thereby shifting land 88 to the right, for. establishing communicationbetween exhaust port 80 and intermediate port 82 for thereby connectingcylinder 106 to exhaust. The pressure in cylinder96 against face 98 ofpiston 90 will thereupon result in shifting of pistons 90, 92 and rack100 to the left. Axial movement of the rack is translated into rotarymovement of shaft 120 to which tracking shoe is secured, it being noted(see 10) that shaft 120 is keyed to a gear segment 122 which is indriving relationship with the teeth 101 of rack 100. Therefore, movementor rack 100 to the left will imparta clockwise rotation to shaft 120 fortilting shoe 20 in a 'clockwise direction, as viewed in Fig. 13, wherebyto shift belt 22 to the left, as viewed in Fig. 4.

1r thelbelt should shift further to the left than its ie determinedcentral position, lever 36 will be moved in a counter-clockwisedirection(as viewed in Fig. 9 whereby spool 38 will beshifted axially to the leftby spring 40, for establishing communication between pressure port 84and intermediate port 82, for introducing pressure media 'via conduits102 intocylinder106 to shift pistons90, 92 and rack 100' "to the right,for thereby tilting shoe 20 in a counter-clockwise direction as viewedin Fig. 13.

With reference to Fig. 9,it will be noted that the relationship betweenthe spool 38 and sleeve 54 may be selectively altered by imparting axialmovement to the sleeve, such as, by way of example, by means of axialmovement of socket 46,tit being noted that socket 46 may be shiftedaxially incident to the application of an endwise movement to shaft 48.I

In order ,to facilitate axial adjustment of shaft 48, a

shaft 142 is providedthrough end plates 66, 78 and body 110,.said shafthaving a spur gear 144 secured to that end whichterminates in well 146of end plate 78. Rotation of gear 144 will drive gear 74 relative toshaft 48, which it threadably engages for'imparting'axial endwisemovement to the shaft which is prevented from rotating by reason of key52 engaging key-way 50 of socket 46, Fig. 10. I

In the preferred embodiment of the invention the other end of shaft 142projects forwardly of end. plate 66, and is provided with a slot 143 toaccommodate the bit of a screwdriver or the like.

As illustrated in Fig. '9, friction means including a friction shoe l45,spring 147, and plug 149 receivable in a suitable bore in housing 110may be provided for precluding accidental end/or unintentional turningof shaft 142.

A knob 35 is preferably secured to and carried by that end of shaft 34remote from clamp 33 (Figs. 6, 7 and 12) for set-up purposes, said knobenabling an operator to conveniently hold shaft 34 in desired positionincident to adjustment of clamp 33 thereto.

Stop pins 21 and '23 (Figs. 4, 7 and 13) are secured to and project frombody on opposite sides of shaft for limiting the maximum tilt of shoe20.

In certain instances it is desirable to impart acyclic sidewise movementto a belt, whichmovement may be effectively accomplished by impartingcyclic endwise axial motion to shaft 48 such as by means of an axiallyshiftable rod 150, note Figs. 5, 2 and 3. Axial movement of rod 150 willbe transmitted to spool 38 relative to sleeve 54. Movement of shaft 48to the left results in port 82 being connected to exhaust line 104,thereby exhausting cylinder 106 and causingpistons. 90, 92 and rack 100to shift to the left (Fig.' 10) for turning shaft 120 in a clockwisedirection for tilting shoe 20 'in a clockwise direction in Fig. 13.Conversely, movement of shaft 48 to the right will connect cylinder 106to pressure port 84 for shifting pistons 90, 92 and rack 100 to therightfor turning shaft 120 in a counter-clockwise direction which willtilt shoe 20 (Fig. 13) in a counterclockwise direction.

In Figs. 2 and 3 cyclic axial movement is imparted to shaft 150 by meansof cam 152, which engages end 154 of the shaft. In the preferredembodiment of the invention the eccentricity of cam 152 may be varied,by any suitable means not pertinent to the subject invention. Rotationof cam 152 may be effected by means of motor 156 suitably fastened, bymeans of bracket 158, to structural support 160 of the belt grinder.

It will be understood that rotation of cam 152 will efiect oscillationof shaft 150 which will be transmitted to socket 46 and thence to sleeve54 and spool 38 for actuating shoe 20 for imparting cyclic sidewisemovement of belt 22 as explained above. f

The numeral 163 (Fig. 2) denotes generally any suitable source ofpressure media, such as, by way of example, a fluid pump driven by motor165. The numerals 167 and 169 denote pressure and exhaust conduits whichare in open communication'with pressure and exhaust lines 94 and 104,respectively, note Fig. 5.

It should be understood that the grinder illustrated in Figs. l-3 ismerely an exemplary, rather than a restrictive illustration of the useto which the servo tracking device may be put. In Fig. l the letters Aand B denote generone or both of said pulleys being suitably driven bymeans not pertinent to the subject disclosure.

From the foregoing it will be noted that the subject device isselectively operable either for fully automatic,

servo operation, wherein all'motion of the tracking shoe 20 is initiatedby reason of belt-actuated movement of finger 30. When thus used thedevice will automatically and efiiciently maintain an endless beltpassing thereover in predetermined axial alignment.

When it is desired to utilize the device for imparting a regular,periodic, or cyclic motion to the tracking shoe for shifting belt 22sidewise thereon, suitable means, such as, by way of example, cam 152,may be utilized for imparting valve actuating movement to the servovalve for superseding the finger-actuated control of the valve. Finger30 will, of course, always bear; against an edge of belt 22, however thecontrolling motion of said finger for actuating valve spool 38 relativeto sleeve 54 is superseded by movement of the sleeve relative to thespool via movement of sockets 46 and 56. V

The phrase endless member" as used-in thespecification and-claimsrefersnot only to endless members in a strict or literal sense, but islikewise meantto include and'comprehend continuous lengths of stripmaterial 744. .4. a Ma's.

7 having? appreciable wi'dthsuch example,

strips of papers metal, etc..- r

To summarize, it will be: noted that the subject servo beltv trackercomprises a hydraulically actuated feed back mechanism in which a finger30', loaded: by spring 4'0 with about one ounce force'against edge": 16belt 22, controls the position of the servo plunger which inturncontrols. the: flow of oil to a cylinder actuating a shoe 20 over which:the: backof the belt tra vlo; As thebelt moves out of its predeterminedpath, the movement is transmitted mechanically to the servo valveplunger. Plunger movement directs oil, under pressure, to positionthe'tr'acking: shoe, urging the belt'baelet'owaa d the correct path. Asthe belt: moves back, the'feelen finger follows, thusl neutralizing the;servo plunger ment. 'This' system: has? proved to be a highly efiicientmeans for controlling the: belt path withina: few thew sandths. I Itshould be understood: that various changes in the structural details: ofthe device maybe made, within the scope of. the: appendedclaims,.-"wit-hout departing; firom the spirit: of the invention.

What: is claimed is: 1. a

1. A tracking. device for endless'members; said device comprising atiltable trackin gi slroe adapted to support and guide an endless memberpassing thereover; anfoscililatable finger adapted to hear against theside edgeof said endless member, a reciprocabl'e motor; driving meansconnecting. the motor to the. shoe, said driving means adapted toconvert thenlinealt motion of. the motor into turning motion of theshoe, motor control means adapted to control the operatingcharacterijstic s of the motor, and means connecting the finger tothemotor control means for translating movement of the finger induced bysidewise movement of the belt. relative to'theshoe into movement of themotor control, whereby the motor is actuated for tilting the shoe" to'shift the endles member sidewise thereof.

2. A tracking device for endless membersjsaid device comprising atiltable tracking shoe adapted to support and guide an endless memberpassing thereover, an oscillatable finger adapted to bear against a sideedge of said endless member, means yieldably maintaining said finger incontacting relationship with the edge of the endless member, areciprocable motor, driving means connecting the motor to the trackingshoe, said driving means adapted to convert the lineal motion of themotor into turning motion of the shoe, a servo valve adapted toselectively control the operating cycle and direction of reciprocationof the motor, and means connecting the finger relative to the valve fortranslating movement of the finger to control and actuate the servovalve whereby the motor is actuated for tilting the tracking shoe toshift the endless member sidewise thereof.

3. A tracking device for an endless belt, said device comprising atiltable tracking shoe adapted to support and guide an endless beltpassing thereover, an oscillatable finger adapted to bear against theside edge of said belt, a reciprocable motor, driving means connectingthe motor to the shoe, said driving means adapted to convert the linealmotion of the motor into tilting motion of the shoe, a servo valveincluding a reciprocable spool, said valve being adapted to control theoperating cycle and direction of reciprocation of. the motor, and meansconnecting the finger relative to the valve spool for translatingbelt-induced movement of the finger into axial movement of the valvespool, whereby the motor is selectively actuated for tilting the shoe to'shift the belt sidewise thereof.

4. A tracking device for an endless belt, said device comprising atiltable tracking shoe adapted to'support and guide an endless beltpassing thereover, an oscillatable finger adapted to bear against a sideedge of said belt, means yieldably maintaining said finger in contactingrelationship with the edge of the belt, a reciprocable motor, driving.means connecting the motor to" the traelt ing shoe, said driving meansadapted to, convert tlie lineal motion of the motor into turningmotionof the slice, a servo valve, said valve iucruding a spool and a sleevehaving a spool-receptive bore: therein, said here and guide an endlessbelt passing thereover,-an 'o's'cillatable' finger adapted fo bearagainst the side edge of said belt, a reciprocable pistomtype motor,driving'means connecting the motor to the shoe, said driving meansadapted to convert the lineal motion" of the motor into turning motionof the shoe, a servo valve including a spool and a reciprocable sleeve"having a spool-receptive bore therein, said sleeve including ports, saidspool having lands adapted 'to co-operate with the ports of the sleeveand being adapted to control theoperation and, direction ofreciprocation of the motor by control ling the flow of actuating mediato the motor, a lever engaging the spo'ol',means connect'ingthe fingerto the lever for translating movement of the finger to movement of thelever'for shifting the spool relative to the sleeve, and yieldable"means normally shifting" the spool in one direction relative to thesleeve, said means comprising? the sole means for yieldably maintaining'the finger in contacting" relationship with the-edge of the belt. I V

6; A tracking d'eviceas described in claim 5}, wherein the length of thetracking shoe is at least equal to the Width of the endless-"beltcontrolled thereby, and wherein the said driving means comprises thesole support for the said shoe.

7. A tracking device for an endless belt, said device comprising atiltable tracking shoe adapted to guide an endless belt passingthereover, and a housing including an oscillatable finger adapted tobear against a side edge of said belt, means yieldably maintaining'saidfinger in contacting relationship with the edge of the belt, a fluidactuated reciprocable motor, driving means including a shaft projectingfrom the housing connecting the motor to the tracking shoe which issecured to and carried by said shaft, said driving means adapted toconvert the lineal motion of the motor into turning motion of the shoe,a servo valve, said valve adapted to control the flow of actuating fluidto said motor for selectively controlling the operating cycle anddirection of reciprocation of the motor, and means including a secondshaft projecting from the housing connecting the finger which is securedto and carried by the second shaft in actuating relationship with thevalve.

8. A tracking device for an endless belt, said device comprising atiltable tracking shoe adapted to support and guide an endless beltpassing thereover, an oscil-' latable fingeradapted to bear against theside edge of said belt adjacent the shoe, a fluid actuated reciprocablemotor, driving means connectingthe motor to the shoe, said driving meansadapted to convert the lineal mo tion of the motor into turning motionof the shoe, a servo valve including a spool and a sleeve having aspool-receptive bore therein, said sleeve including ports, said spoolhaving lands adapted to co-operate with the ports of the sleeve andbeing adapted to control the operation and direction of reciprocation ofthe motor by controlling the flow of actuating fluid to the motor,

means operatively interconnecting the finger to the spool r for shiftingthe spool relative to the sleeve, and means InOllIlJliHg thesleeve foraxial movement relative tothe spoon A tracking device for an endlesbelt, said device comprising a tiltable tracking shoe adapted to supportand guide an endless belt passing thereover, an oscillatable fingeradapted to bear against'a side edge of the belt, a fluid-actuatedreciprocable motor, driving means connecting the motor to the shoe,saidpdriving means adapted to convert the lineal motion of the motorinto turning motion of the shoe, a servo valve, said valve including ahousing, a spool, and a sleeve having a spool-receptive bore therein,said sleeve including ports, said spool having lands adapted toco-operate with the ports of the sleeve and being adapted to control theoperation and direction ofreciprocation of the motor by controlling theflow ofactuating fluid to the motor, means operatively connecting thefinger to the spool for shifting the spool relative to the sleeve,yieldable means normally shifting the spool in onedirection relative tothe sleeve, said means comprising the sole agency for yieldablymaintaining the finger in contacting relationship with the edge of thebelt, means mounting the sleeve for axial movement relative to thehousing and spool, and means operable to impart axial movement to thesleeve.

10, A tracking device for an endless belt, said device comprising atiltable tracking shoe adapted to support and guide an endless beltpassing thereover, an oscillatable finger adapted to bear againstasideedge of the belt, a fluid-actuated reciprocable motor, driving meansconnecting the motor to the shoe, said driving means adapted to convertthe lineal motion of the motor into turning motion of the'sho e, a servovalve, said valve including a housing, a spool and a sleeve having aspool-receptive bore therein, said sleeve including ports, said spoolhaving lands adapted to co-operate with the ports t the sleeve and beingadapted to control the operation and direction of reciprocation of themotor by controlling the flow of actuating fiuidto the motor, meansoperatively connecting the finger to the spool for shifting the spoolrelative to the sleeve,

yieldable means normally shiftingthe spool in one direction relative tothe sleeve, saidmeans comprising the soleagencygfor;yieldablyim'aintaining the finger in contacting relationship,with the edgeof the belt, means mounting the sleeve for axial movementrelative to the housing and spool, yieldable meanslnormally shifting thesleeve in one. directio'nrelative to the housing and spool, and meansoperable to 'impartaxial' movement to the sleeve for altering theinitial relationship between theports and lands. f

11. A tracking device for an endless belt, said deviceselectivelyoperablev for belt-induced and cyclic operationand'comprising a tiltable tracking shoe adapted to supportandlguideaniendless belt passing thereover, a fluid actuated reciprocable motor,driving means connecting the motor to .the tracking shoe, said drivingmeans adapted to convert the lineal 'motionof the motor into turningmotion of the shoe, a servo valve, said valve adapted to control theflow of actuating fluid to said motor for selectively controlling theoperating cycle and direction of reciprocation of the motor, anoscillatable finger adapted to bear against a side edge of said belt,means connecting the finger in actuating relationship with the valve fortranslating belt-induced movement of the finger to tilting movement ofthezshoe," other means in actuating relationship with the valve, drivemeans for imparting cyclic 'operationato said last mentioned means forimparting periodic tilting movement to the shoe, said last mentionedvalve actuating means, when actuated, superseding the finger actuatedcontrol of the valve.

References Cited in the file of this patent UNITED STATES PATENTS2,114,716 Kunzle Apr. 19, 1938 2,182,923 Mehaffey Dec. 12, 19392,331,030 King Oct. 5, 1943 2,587,603 (123136016 Mar. 4, 1952 2,597,256Murray May 20, 1952

